不同浓度水杨酸诱导桉树抗焦枯病保护酶活性变化

摘要

Taking the resistant cuhivar Eucalyptus grandis × E.urophylla of 11 eucalyptus cultivars collected in Fujian as materials,and spraying the leaves with the concentrations of 0,1.0,1.5,2.0,2.5 and 3.0 mmol,L-1 of exogenous plant growth substances salicylic acid (SA) to improve eucalyptus resistance against Cylindrocladium quinqueseptatum,it was discovered that SA effectively induced eucalyptus to improve resistance against C.quinqueseptatum.Different concentrations of SA performed distinct induction.With the increasing of the concentration of salicylic acid,peroxidase,phenylalanine ammonialyase,superoxide dismutase and polyphenoloxidase activities in eucalyptus leaves presented the trend of rising first then decline.Among them,when concentration of salicylic acid was 2.0 mmol·L-1,peroxidase,phenylalanine ammonialyase,superoxide dismutase and polyphenoloxidase activities in eucalyptus leaves were the highest.%以前期收集的福建省11个桉树主栽种系中的中抗种系巨尾桉(Eucalyptus grandis×E.urophylla)为试验材料,用浓度为0(CK)、1.0、1.5、2.0、2.5和3.0 mmol· L-1的外源植物生长物质水杨酸(SA)对桉树叶片进行喷雾处理,以提高桉树对焦枯病的抗病性.结果表明,SA能有效诱导桉树提高对焦枯病的抗性,不同浓度SA对桉树的抗病性诱导效果不同.随着SA浓度的增加,桉树叶片中过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)、超氧化物歧化酶(SOD)和多酚氧化酶(PPO)的活性都呈现出先上升后下降的变化趋势.其中,当SA浓度为2.0 mmol· L-时,桉树叶片中POD、PAL、SOD和PPO的活性都最高.